Disaster recovery system and disaster recovery method

ABSTRACT

In the disaster recovery system exemplified by the information processing system, the cloud management node manages the importance information indicating the importance placed on the performance of each application to be executed by the primary site in correspondence with the virtual computer for executing the application, determines the DR method applied to the virtual computer and the application by selection from multiple types of DR methods based on the importance information of the corresponding application for each of the virtual computers, and determines a content of a predetermined set item applied to transfer of data to be used by the virtual computer.

BACKGROUND

The present invention relates to a disaster recovery system and adisaster recovery method, which are adapted to the disaster recoverysystem for providing the disaster recovery configuration, and thedisaster recovery method thereof.

As disclosed in Patent Application Publication No. US2009/0271582, thedisaster recovery (DR) technology has been known, which is configured tohold multiplexed data in a remote site (secondary site) in preparationfor data loss in the primary site owing to a large-scale disaster suchas an earthquake and a fire.

Multiple types of disaster recovery methods have been known. Forexample, the methods of multi-site type and pilot-light type have beenintroduced in the online seminar [retrieved on Sep. 28, 2021], presentedby Kenji FUNASAKI, Yohei ICHISAKI, titled: Utilization of AWS Osakalocal region and Disaster Recovery attained by AWS”.URL:https://dl.awsstatic.com/webinars/jp/pdf/services/20180717_AWS-BlackBelt_OsakaLocalRegion_KIX_DR.pdf.The method of multi-site type is implemented so that the same system asthat of the primary site is constantly operated in the secondary site.Meanwhile, in the method of pilot-light type, the minimum part of thesecondary site is kept in the stand-by state so that the activeenvironment (the same environment as that of the primary site) can beimmediately constructed in response to the need of recovery resultingfrom detection of the failure.

SUMMARY

In the case where the known disaster recovery technology is applied tothe hybrid cloud environment in which the primary site is in theon-premise environment, and the secondary site is in the cloudenvironment, the following problem is presumed to occur. That is,provision of services to customers (users) in the primary site in thenormal time increases usage of the resource at the cloud side of thesecondary site, leading to increase in the resource cost at the cloudside. The service to be used by the customer is provided by theapplication to be executed in the primary site or the secondary site.The required performance may differ depending on the service. Forexample, it is not preferable to provide the low-cost service which maycause the resource cost increase.

In consideration of the foregoing viewpoints, the disaster recoverysystem and the disaster recovery method are proposed, which allow costreduction in the overall disaster recovery system while providing thedisaster recovery configuration adapted to the service used by thecustomer.

The present invention provides the disaster recovery system having adisaster recovery configuration which allows a secondary site to recovera virtual computer and an application, which have been executed in aprimary site for supplying services in a normal time in response tooccurrence of failure in the primary site. The system includes theprimary site including a first server system for operating the virtualcomputer which executes the application, and a first storage system forstoring data to be used by the first server system in a storage, thesecondary site including a second storage system for storing backup datafor backing up data used by the first server system in a cloud storage,and a second server system for recovering the virtual computer and theapplication in consideration of a correspondence relation in the primarysite using the backup data stored in the cloud storage upon occurrenceof the failure, and a cloud management node for controlling an operationto construct the disaster recovery configuration including the primarysite and the secondary site, and mediating data transfer fortransferring the backup data from the primary site to the secondarysite. The cloud management node manages importance informationindicating importance placed on a performance of each of theapplications to be executed in the primary site in correspondence withthe virtual computer for executing the application, determines adisaster recovery method adapted to the virtual computer and theapplication by selection from multiple types of the disaster recoverymethods based on the importance information of the correspondingapplication for each of the virtual computers, and determines a contentof a predetermined set item applied to the data transfer of data to beused by the virtual computer based on the importance information of thecorresponding application for each of the virtual computers.

The present invention provides the disaster recovery method implementedby a disaster recovery system provided with a disaster recoveryconfiguration which allows a secondary site to recover a virtualcomputer and an application, which have been executed in a primary sitefor supplying services in a normal time in response to occurrence offailure in the primary site. The disaster recovery system includes theprimary site having a first server system for operating the virtualcomputer which executes the application, and a first storage system forstoring data to be used by the first server system in a storage, thesecondary site having a second storage system for storing backup datafor backing up data used by the first server system in a cloud storage,and a second server system for recovering the virtual computer and theapplication in consideration of a correspondence relation in the primarysite using the backup data stored in the cloud storage upon occurrenceof the failure, and a cloud management node for controlling an operationto construct the disaster recovery configuration including the primarysite and the secondary site, and mediating data transfer fortransferring the backup data from the primary site to the secondarysite. The cloud management node manages importance informationindicating importance placed on a performance of each of theapplications to be executed in the primary site in correspondence withthe virtual computer for executing the application, determines adisaster recovery method adapted to the virtual computer and theapplication by selection from multiple types of the disaster recoverymethods based on the importance information of the correspondingapplication for each of the virtual computers, and determines a contentof a predetermined set item applied to the data transfer of data to beused by the virtual computer based on the importance information of thecorresponding application for each of the virtual computers.

The present invention allows cost reduction in the overall disasterrecovery system while providing the disaster recovery configurationadapted to the service used by the customer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a hardware configuration exampleof an information processing system 1 according to an embodiment of thepresent invention;

FIG. 2 illustrates how the information processing system 1 is operated;

FIG. 3 illustrates control information and a control program, which arestored in a memory 302;

FIG. 4 is a view of an example of VM application management information410;

FIG. 5 is a view of an example of application importance managementinformation 420;

FIG. 6 is a view of an example of importance DR management information430;

FIG. 7 is a view of an example of DR management information 440;

FIG. 8 is a flowchart representing a processing procedure example ofdata transfer destination determination processing;

FIG. 9 is a flowchart representing a processing procedure example oftransfer data compression method determination processing;

FIG. 10 is a flowchart representing a processing procedure example ofdata transfer network determination processing;

FIG. 11 is a flowchart representing a processing procedure example ofdata transfer processing;

FIG. 12 is a flowchart representing a processing procedure example ofdisaster recovery processing using a method of pilot-light type; and

FIG. 13 is a flowchart representing another processing procedure exampleof transfer data compression method determination processing.

DETAILED DESCRIPTION

An embodiment of the present invention will be described referring tothe drawings.

The following embodiment will be described for illustrative purposes byomitting and simplifying the explanation to clarify the description. Allcombinations of characteristics described in the embodiment are notnecessarily essential for the solution provided by the invention. Thepresent invention is not limited to the embodiment. All applicationsconforming to the idea of the present invention may be contained in thetechnical scope of the present invention. A person skilled in the art iscapable of implementing the present invention through various additionsand modifications within a scope of the invention. The present inventionmay be implemented in various forms, and provided with either singlecomponent or multiple components unless otherwise restricted.

In the following description, the term “table” is used for explainingthe information of the present invention. However, the information doesnot have to be expressed by the data structure using the table. It maybe expressed as the data structure such as “list” and “DB (database)”,or other terms. In order to represent independence from the datastructure, such term as “table”, “list”, and “DB” may be simply referredto as “information”. Upon description of each content of theinformation, it is possible to use such term as “identificationinformation”, “identifier”, “title”, “name”, and “ID”, which can bemutually replaced.

In the following description, the program is executed for conductingprocessing. The program is executed by at least one unit of processor ormore (for example, CPU) so that the specified processing is conductedusing storage resource (for example, memory) and/or interface device(for example, communication port) appropriately. Accordingly, thedescription may be made based on the interpretation that the processingis conducted by the processor as the processing entity. Similarly, theprogram is executed by the processing entity which may be a controller,a device, a system, a computer, a node, a storage system, a storagedevice, a server, a management computer, a client, and a host, whicheverthe processing entity having the processor. The processing entity (forexample, processor) for executing the program may be provided with ahardware circuit which partially or fully conducts the processing, ormay be modulized. For example, the processing entity for executing theprogram may be provided with the hardware circuit which executesencryption/decryption, or compression/decompression. Various types ofprograms may be installed in the respective computers via programdistribution servers and storage media. The processor is operated inaccordance with the program to serve as a function unit for implementinga predetermined function. The device and the system having the processorinclude those function units. The “read/write processing” may bereferred to as “updating processing”.

In each drawing, the common structure is designated with the samereference number. Referring to the drawings, if the explanation will bemade with respect to the similar elements without discriminationthereamong, the reference code or the common number corresponding to thereference code will be used. If the explanation will be made bydiscrimination among the similar elements, the reference code designatedto the element, or the ID allocated to the element may be used in placeof the reference code.

(1) Configuration

FIG. 1 is a block diagram illustrating a hardware configuration exampleof an information processing system 1 according to an embodiment of thepresent invention.

Referring to FIG. 1 , the information processing system 1 as a disasterrecovery system which provides the disaster recovery configurationincludes a primary site 100, a secondary site 200, and a cloudmanagement node 300, which are mutually connected via a network 10(typically, IP (Internet Protocol) network). The embodiment will bedescribed with respect to the disaster recovery configuration using anon-premise-based storage system (on-premise storage) for the primarysite 100, and a cloud-based storage system (cloud storage) for thesecondary site 200. The configuration may be arbitrarily made so long asat least the cloud storage is used for the secondary site. The use ofthe cloud storage for the primary site 100 will keep essential featuresof the present invention unchanged. In the description, the “disasterrecovery” may be abbreviated to DR (Disaster Recovery) for simplifyingthe description.

The primary site 100 is a storage system for providing the user(customer) with services by application in a normal condition, andconstituted of an on-premise storage system. Specifically, the primarysite includes a server system 110, a storage controller 120, and anon-premise storage 130.

The server system 110 includes a processor 111, a memory 112, and anetwork interface (I/F) 113, and is connected to the network 10 via theI/F 113. The storage controller 120 includes a memory 122, a front-endnetwork interface (I/F) 124, a back-end storage interface (I/F) 123, anda processor 121 which is connected to the memory and the interfaces. Thestorage controller 120 is connected to the server system 110 via the I/F124, and to the on-premise storage 130 via the I/F 123. The on-premisestorage 130 is a storage device for physically storing data. Thememories and processors of the server system 110 and the storagecontroller 120 are made redundant, respectively.

The memory 122 stores information, and one or more programs. Theprocessor 121 executes the one or more programs to process an I/O(Input/Output) request such as provision of a storage region (describedas the logical volume) to the server system 110, the write request andthe read request from the server system 110. For example, the serversystem 110 receives the write or read request designating the volumefrom the upper device (host) operated by the user (customer), and suchrequest is transmitted to the storage controller 120. In response to thewright or read request, the storage controller 120 reads/writes datacorresponding to the volume in the on-premise storage 130.

The storage controller 120 and the on-premise storage 130 may beintegrated into a single storage system, for example, the high-endstorage system and the storage system using flash memory by RAID(Redundant Array of Independent (or Inexpensive) Disks) technology.

The on-premise storage 130 may be configured as a node group (forexample, distribution system) with multi-node structure which includesmultiple storage nodes each having a storage device. Each of the storagenodes may be a general-purpose physical computer. Each of the physicalcomputers executes the predetermined software to allow construction ofSDx (Software-Defined anything). For example, SDS (Software-DefinedStorage) or SDDC (Software-Defined Datacenter) may be employed for theSDx. The on-premise storage 130 may be configured as the system whichimplements the function serving as a hyper convergedinfrastructure-based storage system, for example, the host system forissuing the I/O request (an execution body (for example, virtual machineand container) of the application for issuing the I/O request), and thefunction serving as the storage system for processing the I/O request(for example, execution body of the storage software (virtual machineand container)). The foregoing configuration of the on-premise storage130 is an exemplified case, which is not limited to the one as describedabove.

The secondary site 200 serves as a disaster recovery site (DR site) forholding data stored in the primary site 100 in case of data loss whichoccurs therein owing to a large-scale disaster such as an earthquake anda fire. Upon failure in the primary site 100, the data held in thesecondary site are used for recovering those data and services of theprimary site 100. The secondary site 200 of the information processingsystem 1 according to the embodiment typically belongs to the publiccloud, which serves as the cloud storage system functioning as a base ofthe cloud storage service provided by the cloud vendor. For example,AWS® (Amazon Web Services), Azure®, Google Cloud Platform®, and the likemay be employed for the cloud storage service. As for the cloud storagesystem for the secondary site 200, the storage system belonging to thecloud of other type (for example, private cloud) may be employed inplace of the public cloud. A configuration of the public cloud will bedescribed as an exemplified case.

The secondary site 200 includes a server system 210 and a storage system220, and is connected to the network 10.

The server system 210 includes a processor 211 and a memory 212 (astorage may further be included), and a network interface (not shown),and is connected to the network 10 via the network interface. A storagesystem 220 includes storages with different performances and capacitycosts, for example, a high-cost first storage device 221 for high-end,and a low-cost second storage device 222 with large capacity. Each ofthe first storage device 221 and the second storage device 222 includesa part which is the same as that of the storage controller 120, and aphysical data storage part. As a specific example of the storage system220, the first storage device 221 corresponds to the block storageprovided by the storage service so called “EBS” in the AWS®, and thesecond storage device 222 corresponds to the object storage provided bythe storage service so called “S3” in the AWS®. The object storage has afeature of being incapable of performing data synchronization.

A cloud service management 230 is a component which implements thefunction of managing overall cloud services. Normally, the cloud is usedto construct the environment required by the user through the process inwhich the cloud service management 230 in the cloud service receives theuser's request, and the resource adapted to the user's request isselected from those with multiple different specifications in the cloud.This applies to the secondary site 200 according to the embodiment. Theserver system (that is, the server system 210) and the storage system(storage system 220) may be the main resource in the cloud service. Thecloud service management 230 may be an appliance (dedicated device) or aphysical computer. The cloud service management 230 may be formed as apart of the server system 210, or provided in the cloud management node300. An explanation will be made with respect to the cloud servicemanagement as the program stored in a single unit of the memory 212 ofthe server system 210 in the cloud service (referring to FIG. 1 , it isillustrated as the structure separated from the memory 212 of the serversystem 210 in the secondary site 200 for easy understanding).

The cloud management node 300 is an appliance for executing control ofconstructing the DR configuration constituted by the primary site 100and the secondary site 200, and mediating the data transfer between theprimary site 100 and the secondary site 200. For example, the cloudmanagement node 300 may be in the cloud service or in the cloud servicemanagement 230 in the secondary site 200. An explanation will be madewith respect to the cloud management node 300 exemplified by a physicalcomputer including a memory 302 and an I/F 303, and the processor 301connected to those components.

The information processing system 1 as illustrated in FIG. 1 isconfigured to directly transfer data between the on-premise storage 130in the primary site 100 and the cloud storage in the secondary site 200(first storage device 221, the second storage device 222) via thenetwork 10. However, the data transfer method is not limited to the oneas described above. Data may be transferred using another network pathor line for data transfer. The essence of the present invention does notlie in specific types of various networks and lines.

The network 10 may be connected to the storage management system. Forexample, the storage management system is a computing system (one ormore computers) for managing a storage area configuration of theon-premise storage 130, and allows the user to give an instruction withrespect to a setting related to the on-premise storage 130.

FIG. 2 illustrates how the information processing system 1 is operated.

As FIG. 2 illustrates, in the primary site 100, one or more VMs 152 aregenerated on a server (server group) 151 constituted by one or moreserver systems 110. The VM 152 is a virtual machine on which theapplication 153 designated by the user is executed. The application 153designated by the user serves to supply services to the user.Specification of the service to be used by the user allows designationof the application 153 corresponding to the service.

In the primary site 100, capacity virtualization technology allowsstorage of data in the storage region within the on-premise storage 130via a pool 140. A storage control program 125 is stored in the memory122 of the storage controller 120 for controlling the on-premise storage130. A copy function 126 is a function (or program for the function)implemented by the program stored in the memory 122 of the storagecontroller 120. The function serves to copy data stored in theon-premise storage 130 in the primary site 100 to transfer such data tothe secondary site 200.

The memory 112 of the server system 110 stores VM control information(not shown). The VM control information may be stored in the on-premisestorage 130. The VM control information includes the information forcontrolling the VM 152, for example, the information indicating anamount of resource (for example, volume) to be allocated to each of theVMs 152.

As described above, the application 153 executed on the VM 152 isinstructed by the user. The memory of the server 151 (that is, thememory 112 of the server system 110) stores the information ofcorrespondence between identifiers of the VM and the application 153 tobe executed thereon. Alternatively, the identifier correspondenceinformation may be stored in a not shown storage management system(computing system for managing the storage region configuration of theon-premise storage 130) to be connected via the network 10.

In the information processing system 1, the cloud management node 300acquires the resource configuration information and the applicationinformation of the primary site 100 for issuing an instruction to thecloud service side to construct the DR environment where the secondarysite 200 executes the application (application 253) on the VM (VM 252),which is the same as that of the primary site 100. The resourceconfiguration information and the application information of the primarysite 100 will be stored in the memory 112 of the server system 110 orthe on-premise storage 130. However, the information data may be storedin the not shown storage management system to be connected via thenetwork 10.

As described above, methods at different levels are used forimplementing the disaster recovery (DR). The DR methods at differentlevels may be used by the information processing system 1 according tothe embodiment. The user is allowed to give an instruction to use theselected DR method, or the system side may be configured toautomatically select the DR method. The DR method may be designated in aunit of VM or volume. An explanation will be made herein with respect tothe DR method to be designated for each VM as an exemplified case.

Importance placed on the performance of the application executed on thevirtual machine (VM) for providing services is variable depending on theapplication. For example, some application may have the performanceplaced with the highest importance, and some application may beconsidered as being allowable even if RTO (Recovery Time Objective) islowered to a slight degree. The information processing system 1according to the embodiment is configured to manage “importance”information indicating the importance placed on each performance of theapplications 153 to be executed on the VM 152. Based on the importanceinformation, the disaster recovery level adapted to each of the VMs (DRmethod) is selected to construct the cloud DR configuration.

Specifically, referring to FIG. 2 , if higher importance is placed onthe performance of the “application 2” to be executed on the “VM2” inthe primary site 100, the method of multi-site type is selected for the“VM2” in the cloud of the secondary site 200 so that the server resourcefor the “application 2” with higher importance is secured immediatelyafter starting construction of the DR configuration. Meanwhile, if lowerimportance is placed on the performance of the “application 1” to beexecuted on the “VM1” in the primary site 100, the method of pilot-lighttype is selected for the “VM1” in the cloud of the secondary site 200 soas not to secure the server resource for the “application 1” with lowerimportance when starting construction of the DR configuration. If themethod of pilot-light type is selected for the “VM1”, the serverresource for the “application 1” is secured upon switching of the siteto be operated from the primary site 100 to the secondary site 200.

Utilizing the application importance information to be referred uponselection of the DR method, the information processing system 1according to the embodiment implements the data transfer method and datatransfer destination storage device selection method in accordance withthe importance, or the method derived from combining those methods fordata transfer between the primary site 100 and the secondary site 200.This makes it possible to attain cost reduction of the cloud DR.

An explanation will be briefly made with respect to the DR environmentconstruction procedure conducted by the information processing system 1according to the embodiment.

The “importance” information of the application 153 in the primary site100 is processed on the assumption to be described blow. For example,the cloud management node 300 (processor 301) determines the application“importance” information from the result derived from the command or theuser's instruction through an input operation from the GUI (GraphicalUser Interface) for user's input, the result derived fromcollection/analysis of the information by the cloud management node 300,or the like. Such “importance” information is preliminarily registeredin application importance management information 420 in the memory 302of the cloud management node 300 (detailed explanation will be madelater referring to FIG. 5 ). In the example to be described in theembodiment, the application 153 as the “application 1” to be executed onthe VM 152 as the “VM1” has the lower importance, and the application153 as the “application 2” to be executed on the VM 152 as the “VM2” hasthe higher importance.

The cloud management node 300 (processor 301) refers to the importanceinformation registered in the application importance managementinformation 420 to determine the DR method in accordance with theimportance, and registers the DR method in importance DR managementinformation 430 (detailed explanation will be made referring to FIG. 6). As described above, the application to be executed on the VM may bethe one having its performance placed with higher importance, or the oneregarded as being allowable even if the RTO is lowered to a slightdegree (the performance is placed with low importance). Accordingly, theVM for executing the application having its RTO placed with higherimportance (that is, application with high importance) is used forconstructing the DR environment by the method of multi-site type. The VMfor executing the application having deterioration in the RTO regardedas allowable (that is, application with low importance) is used forconstructing the DR environment by the method of pilot-light type.

Specifically, the cloud management node 300 receives the VM controlinformation of the primary site 100 and the information of theapplication 153 to be executed on the VM 152 from the primary site 100,and manages the information data in the VM application managementinformation 410. The cloud management node 300 then selects the DRmethod corresponding to the VM 152 (VM 252) with reference to theimportance information, and gives an instruction on DR environmentconstruction request to the secondary site 200.

The cloud service management 230 in the secondary site 200 selects theresource in the cloud in accordance with the request for the DRenvironment construction, and executes allocation of the resource.

In the case of the DR configuration corresponding to the application 1with low importance, the resource such as the server system is notsecured in the DR destination (secondary site 200) in the normal state,and the resource is secured upon start of the fail-over in response tooccurrence of failure. Referring to the secondary site 200 in FIG. 2 ,the “application 1” with low importance (application 253), the “VM1” forexecuting the application (VM 252), and the server 251 for generatingthe VM are shown by broken lines. In the method of pilot-light type,data in the primary site 100 are constantly transferred to the DRdestination despite the DR configuration as described above.

In the DR configuration corresponding to the application 2 with highimportance, normally, the same server environment as that in the primarysite 100 is constructed in the DR destination (secondary site 200). Thedata in the primary site 100 are constantly transferred to the DRdestination. The method of multi-site type is implemented to execute theforegoing processing.

In the cloud, the resource usage charge is generated upon allocation ofthe resource. Accordingly, the use of the resource is minimized untilthe need of allocating resource to the application with low importanceas described above so that the DR cost can be reduced.

A DR management program 460 (see FIG. 3 ) of the cloud management node300 transfers data in the primary site 100 into the secondary site 200via the cloud management node 300. Data are transferred between theprimary site 100 and the secondary site 200 by implementing the methodselected from various data transfer methods of multiple types. Theprocess of determining the method will be described referring to FIG. 8.

FIG. 3 illustrates control information and a control program, which arestored in the memory 302. As illustrated in FIG. 3 , the memory 302 ofthe cloud management node 300 stores such control information as the VMapplication management information 410, the application importancemanagement information 420, the importance DR management information430, and the DR management information 440. Specific examples of thecontrol information data will be illustrated in FIGS. 4 to 7 . Thememory 302 stores a not shown program.

The DR management program 460 issues an instruction to construct the DRenvironment between the primary site 100 and the secondary site 200,forms a pair of the VM and the application corresponding to the DRenvironment, and controls data transfer from the primary site 100 to thesecondary site 200.

FIG. 4 is a view of an example of the VM application managementinformation 410. The VM application management information 410 includesmanagement information relating to the VM 152 generated on the server151 in the primary site 100. The VM application management information410 as an example illustrated in FIG. 4 is constituted by fieldsincluding a VM 411, an application 412, a DR method 413, a transferdestination 414, a compression method 415, a transfer method 416, and anetwork 417.

The VM 411 stores an identifier which identifies the VM 152. Theapplication 412 stores an identifier of the application 153 to beexecuted on the VM. For example, FIG. 4 represents that the “VM1”executes the “application 1”, and the “VM2” executes the “application2”. The DR management program 460 acquires corresponding information ofthe VM 411 and the application 412 from the primary site 100 so thatsuch information is preliminarily registered in the VM applicationmanagement information 410.

The DR method 413 stores the type of DR method for executing DR of theVM 152. Information of the DR method 413 is processed as describedbelow. The cloud management node 300 (DR management program 460) refersto the application importance management information 420 and theimportance DR management information 430 to determine the DR method inaccordance with the importance of the application 153, and registers thedetermination result. Specifically, in the embodiment, the DR managementprogram 460 determines to select the method of multi-site type whichallows construction of DR environment of the VM 152 for executing theapplication 153 with “high” importance, and to select the method ofpilot-light type which allows construction of DR environment of the VM152 for executing the application 153 with “low” importance. That is,the “multi-site” type is registered as the DR method 413 for the “VM2”which executes the “application 2”. The “pilot-light” type is registeredin the DR method 413 for the “VM1” which executes the “application 1”.Determination of the DR method is adaptable to the service desired bythe customer.

The transfer destination 414 stores storage model information of the DRdestination (strictly, the transfer data storage destination).Specifically, as the “VM1” executes the “application 1” with lowimportance, the performance of the storage model of the transferdestination of the DR is not placed with high importance. In the case asillustrated in FIG. 4 , “S3” is registered as the storage service whichexhibits excellent cost performance, and has capacity with no upperlimit in the transfer destination 414 corresponding to the “VM1”.Meanwhile, as the “VM2” executes the “application 2” with highimportance, the “EBS” is registered as the high-performance storageservice in the transfer destination 414 corresponding to the “VM2”. Thestorage model information to be stored in the transfer destination 414is not limited to the name of the device. Such information may be theidentifier indicating the storage class, for example, high-end,midrange, or the like. The information in the transfer destination 414is determined and registered through execution of the data transferdestination determination processing (see FIG. 8 ) by the DR managementprogram 460 to be described later.

The compression method 415 stores information of a compression algorithmtype for storing data to be used by the VM 152 in the storage device.The information processing system 1 provides multiple types ofcompression algorithms (compression methods) each having differentfeature relating to the data compression/decompression. It is assumedthat among those algorithms, the “algorithm 1” as shown in FIG. 4 is thecompression algorithm with high data compression ratio, and the“algorithm 2” is the compression algorithm for decompressing thecompressed data at high speeds (in other words, short decompressiontime). The DR management program 460 acquires the correspondinginformation from the primary site 100, and executes the transfer datacompression method determination processing (see FIG. 9 ) to bedescribed later so that the information of the compression method 415 isdetermined and registered. Specifically, the case in FIG. 4 shows thatthe “algorithm 1” is registered in the compression method 415corresponding to the “VM1”, and the “algorithm 2” is registered in thecompression method 415 corresponding to the “VM2”. As this caserepresents, the data used for the “VM1” are stored in the on-premisestorage 130 while having data compressed using the “algorithm 1”, andthe data used for the “VM2” are stored in the on-premise storage 130while having data compressed using the “algorithm 2”.

The transfer method 416 stores the data transfer method to beimplemented for data transfer from the primary site 100 to the secondarysite 200. The data transfer method to be stored in the transfer method416 may be “synchronous copy” for copying data synchronously, and“asynchronous copy” for copying data asynchronously. However, other datatransfer method may be selected. The information of the transfer method416 is determined and registered through execution of the data transferdestination determination process (see FIG. 8 ) to be described later bythe DR management program 460.

The network 417 stores the information indicating the network typedefined by the line type to be used, the band or the like with respectto the data transfer path (network) from the primary site 100 to thesecondary site 200. Referring to FIG. 4 , the “low speed” denotes theuse of the low-cost network band at low communication speed, and the“high speed” denotes the use of the high-cost network band at highcommunication speed. The information of the network 417 is determinedand registered through execution of the data transfer networkdetermination process (see FIG. 10 ) to be described later by the DRmanagement program 460.

FIG. 5 is a view of an example of the application importance managementinformation 420. The application importance management information 420includes information indicating the importance placed on the application153 to be executed on the VM 152. The application importance managementinformation 420 in FIG. 5 includes fields of an application 421 and animportance 422.

The application 421 stores an identifier for identifying the application153 to be executed on the VM 152. The importance 422 stores the“importance” preliminarily placed on the performance of the application.The “importance” of the application may be designated and registered bythe user, or automatically set by the computer side through analysis ofthe past information. Referring to the case as illustrated in FIG. 5 ,the “application 1” is registered as the application with “low”importance, and the “application 2” is registered as the applicationwith “high” importance. The value stored in the importance 422 may be anidentifier, a numerical value, or the like, which allows identificationof the “importance”. An arbitrary number of stages of the importance maybe set so long as it is set to the value equal to or more than 2. The“importance” of the application is preliminarily set. However, it ispossible to change the “importance” in the middle of operating thesystem in response to designation or analysis of the program by theuser.

FIG. 6 is a view of an example of the importance DR managementinformation 430. The importance DR management information 430 includesDR method information corresponding to the importance of the applicationregistered in the importance 422 of the application importancemanagement information 420. The importance DR management information 430represented in FIG. 6 as an example includes fields of an importance 431and a DR method 432.

The importance 431 stores the importance of the applicationpreliminarily set in accordance with the importance placed on theapplication performance. The importance corresponds to the importance422 registered in the application importance management information 420.The DR method 432 stores the DR method corresponding to the importanceof the application. Each of the importance DR management information 430is preliminarily registered by the user. Referring to the importance DRmanagement information 430 in FIG. 6 , in the case of DR of theapplication with low importance, the DR environment is constructed bythe method of pilot-light type. In the case of DR of the applicationwith high importance, the DR environment is constructed by the method ofmulti-site type.

FIG. 7 is a view of an example of the DR management information 440. TheDR management information 440 includes information indicating arelationship (related to DR) of the corresponding pair in the DRenvironment. The DR management information 440 as an exemplary case inFIG. 7 includes fields of a primary 441 and a secondary 442,respectively.

The primary 441 stores identifiers indicating the respectiveconfigurations (primary site 100, VM 152, and the like) at the primaryside of the DR. The secondary 442 stores identifiers indicating therespective configurations (secondary site 200, VM 252, and the like) atthe secondary side of the DR.

(2) Processing

A detailed explanation will be made with respect to processing to beexecuted by the information processing system 1 for constructing the DRenvironment using the above-described configuration.

(2-1) Data Transfer Destination Determination Processing

FIG. 8 is a flowchart representing a processing procedure example of thedata transfer destination determination processing. The data transferdestination determination processing is executed for determining thedata transfer destination storage and the data transfer method for datatransfer from the primary site 100 to the secondary site 200. Theprocessing for each of the VMs 152 is executed by the DR managementprogram 460 of the cloud management node 300 for each of the VMs 152.

As FIG. 8 represents, with reference to the VM application managementinformation 410 and the application importance management information420, the DR management program 460 acquires importance of theapplication 153 to be executed by the VM 152 as a processing object(step S101).

The DR management program 460 confirms whether the importance of theapplication, which has been acquired in step S101 satisfies apredetermined determination criterion of the importance (step S102). Inaccordance with the determination result, the storage resource class ofthe data transfer destination (or the storage model which can bedesignated as the cloud service) is determined from the storageresources in the cloud service (secondary site 200) as the DRdestination. Referring to the processing example in FIG. 8 , if theimportance of the application, which has been acquired in step S101 is“high” (YES in step S102), the process proceeds to step S103. If theimportance of the application, which has been acquired in step S101 is“low” (NO in step S102), the process proceeds to step S105.

When the process proceeds from step S102 to step S103, the DR managementprogram 460 determines the high-end storage device in the cloud as thedata transfer destination to which data used by the VM 152 as theprocessing object are transferred. The determined content is thenregistered in the transfer destination 414 of the VM applicationmanagement information 410. Specifically, the first storage device 221is determined as the data transfer destination to which data used by theVM2 for executing the application 2 with high importance aretransferred. Then the “EBS” as the model information of the firststorage device 221 is registered in the transfer destination 414corresponding to the VM2 (application 2).

In the subsequent step S104, the DR management program 460 determinesthe data transfer method, and the determined content is registered inthe transfer method 416 of the VM application management information410. Determination of the high-end storage device (first storage device221) as the data transfer destination in step S103 indicates that thedata of the application 2 with high importance are important whilehaving the RPO (Recovery Point Objective) placed with high importance aswell. Accordingly, in step S104, the DR management program 460 selectsthe data transfer method utilizing synchronous copy as the transfermethod of the data used by the VM2 from the primary site 100 to thesecondary site 200. The “synchronous copy” is then registered in thetransfer method 416 corresponding to the VM2 (application 2).

Meanwhile, when the process proceeds from step S102 to S105, the DRmanagement program 460 determines the low-cost storage device in thecloud as the transfer destination of data to be used by the VM 152 asthe processing object, and registers the determined content in thetransfer destination 414 of the VM application management information410. Specifically, the second storage device 222 is determined as thedata transfer destination to which the data used by the VM1 forexecuting the application 1 with low importance are transferred. The“S3” as the model information of the second storage device 222 isregistered in the transfer destination 414 corresponding to the VM1(application 1).

Next, in step S106, the DR management program 460 determines the datatransfer method, and registers the determined content in the transfermethod 416 of the VM application management information 410.Determination of the low-cost storage device (second storage device 222)as the data transfer destination in step S105 indicates that the data ofthe application 1 with low importance are regarded as being allowabledespite deterioration in the RTO to a slight degree. In step S106, theDR management program 460 selects the data transfer method utilizingasynchronous copy as the method for transferring data to be used by theVM 1 from the primary site 100 to the secondary site 200, and registersthe “asynchronous copy” in the transfer method 416 corresponding to theVM1 (application 1).

At the end of processing in step S104 or S106, the DR management program460 finishes execution of the data transfer destination determinationprocessing.

The data transfer destination determination processing may be modifiedas described below. For example, in the case of the application withhigh importance, the DR management program 460 may be configured toselect asynchronous copy to be utilized for the data transfer method instep S104. If the storage device as the determined data transferdestination is the object storage, the DR management program 460 selectsthe asynchronous copy to be utilized for the data transfer method as theobject storage has a feature of being incapability of overwriting data.In the case of the asynchronous copy selected to be utilized for thedata transfer method, the DR management program 460 may be configured toselect any one of multiple data transfer methods corresponding to theasynchronous copy. For example, besides the method utilizingasynchronous copy which never attains synchronization, a so-calleddifferential copy may be selected for periodically transferring thedifference in the snap shot.

As described above, the DR management program 460 executes the datatransfer destination determination processing based on the importance ofthe application 153 to be executed on the VM 152. This makes it possibleto appropriately determine the data transfer destination storage and thedata transfer method upon data transfer from the primary site 100 to thesecondary site 200 in accordance with the service used by the customer.

(2-2) Transfer Data Compression Method Determination Processing

FIG. 9 is a flowchart representing a processing procedure example oftransfer data compression method determination processing. The transferdata compression method determination processing is executed fordetermining the compression method of data transferred from the primarysite 100 to the secondary site 200. The DR management program 460 of thecloud management node 300 executes the processing for each of the VMs152.

The information processing system 1 according to the embodimentcompresses the data stored in the on-premise storage 130 in the primarysite 100 by the predetermined compression method (compressionalgorithm), and transfers the compressed data to the secondary site 200so that the data transfer time can be reduced as well as the transfercost. The compressed data transferred to the DR destination (secondarysite 200) will be decompressed as needed (for example, upon start offail-over in response to occurrence of failure in the method ofpilot-right type). This makes it possible to reduce the DR cost in thecloud.

Referring to FIG. 9 , similar to step S101 in FIG. 8 , with reference tothe VM application management information 410 and the applicationimportance management information 420, the DR management program 460acquires the importance placed on the application 153 to be executed bythe VM 152 as the processing object (step S201).

With reference to the application importance acquired in step S201, theDR management program 460 confirms whether the importance satisfies apredetermined determination criterion (step S202), and determines thetransfer data compression method in accordance with the determinationresult. Referring to the processing example as represented in FIG. 9 ,if the application importance acquired in step S201 is “high” (YES instep S202), the process proceeds to step S203. If the applicationimportance acquired in step S201 is “low” (NO in step S202), the processproceeds to step S204.

When the process proceeds from step S202 to step S203, the DR managementprogram 460 selects the compression algorithm which attains highdecompression speed (short decompression time) from the preliminarilyprovided multiple types of compression algorithms, and determines theselected compression algorithm as the transfer data compression method.The determined content is then registered in the compression method 415of the VM application management information 410. As described above,the DR environment for the VM2 which executes the application 2 withhigh importance is constructed by the method of multi-site type.Accordingly, it is essential to transfer the data to the DR destinationin a short time. That is, in the case of data for the application 2 withhigh importance, importance is placed on the compressed datadecompression speed (short decompression time) rather than the high datacompression ratio. Therefore, in step S203, the DR management program460 determines the “algorithm 2” which attains high decompression speedbut does not attain high compression ratio as the data compressionmethod for the application 2 (VM2). The “algorithm 2” is registered inthe compression method 415 corresponding to the VM2 (application 2).

When the process proceeds from step S202 to step S204, the DR managementprogram 460 selects the compression algorithm which attains highcompression ratio from the preliminarily provided multiple types ofcompression algorithms, and determines the selected compressionalgorithm as the compression method to be used for data transfer. Thedetermined content is registered in the compression method 415 of the VMapplication management information 410. As described above, the DRenvironment for the VM1 which executes the application 1 with lowimportance. Accordingly, it is essential to suppress resource usage ofthe DR destination. That is, in the case of data of the application 1with low importance, importance is placed on high data compression ratiorather than the decompression speed of the compressed data (shortdecompression time). Therefore, in step S204, the DR management program460 determines the “algorithm 1” with high compression ratio despiterelatively low speed for decompressing the compressed data as the datacompression method for the application 1 (VM1). The “algorithm 1” isregistered in the compression method 415 corresponding to the VM 1(application 1).

At the end of the step S203 or S204, the DR management program 460finishes execution of the transfer data compression method determinationprocessing.

The foregoing transfer data compression method determination processingis configured to determine the compression algorithm for each of the VMs152. The processing may be modified to allow the DR management program460 to determine the compression algorithm for each volume or each dataregion in the single volume.

(2-3) Data Transfer Network Determination Processing

FIG. 10 is a flowchart representing a processing procedure example ofthe data transfer network determination processing. The data transfernetwork determination processing is executed for determining the networktype to be used for data transfer between the primary site 100 and thesecondary site 200. The DR management program 460 of the cloudmanagement node 300 executes the processing for each of the VMs 152.

Referring to FIG. 10 , like the step S101 in FIG. 8 and the step S201 inFIG. 9 , with reference to the VM application management information 410and the application importance management information 420, the DRmanagement program 460 acquires the importance of the application 153 tobe executed by the VM 152 as the processing object (step S301).

With reference to the application importance acquired in step S301, theDR management program 460 confirms whether the importance satisfies apredetermined determination criterion (step S302), and determines thenetwork type to be used for data transfer to the VM 152 as theprocessing object in accordance with the determination result. Referringto the processing example in FIG. 10 , if the application importanceacquired in step S301 is “high” (YES in step S302), the process proceedsto step S303. If the application importance acquired in step S301 is“low” (NO in step S302), the process proceeds to step S304.

When the process proceeds from step S302 to S303, the DR managementprogram 460 determines the high speed/cost network band as the networktype for transferring data to be used by the VM 152 as the processingobject, and registers the information indicating the determined contentin the network 417 of the VM application management information 410.Specifically, the RTO of data for the application 2 with high importanceis regarded as being highly important. In step S303, the DR managementprogram 460 determines to transfer data from the primary site 100 to thesecondary site 200 using the high-speed (high-cost) network band, andregisters “high speed” in the network 417 corresponding to the VM2(application 2) as the information indicating the determined networktype. The high-speed network may be exemplified by AWS Direct Connect.

Meanwhile, when the process proceeds from step S302 to step S304, the DRmanagement program 460 determines the low-speed/cost network band as thenetwork type for transferring data to be used by the VM 152 as theprocessing object, and registers the information indicating thedetermined content in the network 417 of the VM application managementinformation 410. Specifically, the cost of data for the application 1with low importance is regarded as being important higher than the RTO.In step S304, the DR management program 460 determines to transfer datafrom the primary site 100 to the secondary site 200 using the low-cost(low-speed) network band, and registers “low speed” in the network 417corresponding to the VM1 (application 1) as the information indicatingthe determined network type. The low-speed network may be exemplified bythe internet or the like.

Explanations have been made with respect to the data transferdestination determination processing for determining the data transferdestination and the data transfer method (FIG. 8 ), the transfer datacompression method determination processing for determining the transferdata compression method (FIG. 9 ), and the data transfer networkdetermination processing for determining the network type to be used forthe data transfer (FIG. 10 ). However, all those processing operationsdo not have to be executed by the information processing system 1according to the embodiment. A part of those determination processingoperations may be executed selectively, or combination of multipledetermination processing operations may be executed. If any one of theabove-described determination processing operations is not executed, theuse of alternative means for such determination processing (user'sinstruction and setting of the initial value) allows the information tobe registered in each data field of the VM application managementinformation 410 for each of the VMs.

(2-4) Data Transfer Processing

FIG. 11 is a flowchart representing a processing procedure example ofdata transfer processing. The data transfer processing is executed fordata transfer using the compression algorithm (compression method)determined by the transfer data compression method determinationprocessing as represented in FIG. 9 . The data transfer processing isexecuted by the DR management program 460 of the cloud management node300, and the copy function 126 of the primary site 100.

Referring to FIG. 11 , the DR management program 460 instructs theprimary site 100 to compress data using the compression algorithmregistered in the compression method 415 of the VM applicationmanagement information 410 upon data transfer to the DR destination(step S401). The instruction may be given from the cloud management node300 via the storage management device.

The copy function 126 in the storage controller 120 generates a copy ofdata to be transferred to the secondary site (step S402).

The compression function in the storage controller 120 executes thecompression processing to the data copied by the copy function 126 instep S402 using the designated compression algorithm (step S403). Thecompression function is implemented by the processor 111 for executingthe predetermined program. Although not shown in FIGS. 1 and 2 , thecopy function 126 is allowed to implement the compression function.

The copy function 126 in the storage controller 120 transfers thecompressed data after completion of the compression processing in stepS403 to the secondary site 200 (step S404). The data are transferred inaccordance with the registered information in the VM applicationmanagement information 410.

In the secondary site 200, the cloud service management 230 stores thecompressed data transferred in step S404 in the storage systemcorresponding to the DR environment in the secondary site 200 (stepS405), and finishes the data transfer processing. The storage systemcorresponding to the DR environment is designated by the transferdestination 414 of the VM application management information 410. In thesecondary site 200, the transferred compressed data are stored as theyare so that they are decompressed when needed. This makes it possible toreduce the DR cost of the cloud.

The compression algorithm designated by the compression method 415 ofthe VM application management information 410 may be preliminarilyprovided in the memory within the storage controller 120, or stored inthe storage controller 120 from outside the primary site 100 bydownloading upon reception of the instruction. The compression functionmay be provided in another structure of the primary site 100 withoutbeing limited to the provision in the storage controller 120. Thecompression processing may be executed by the compression function on abackground during data transfer. In this case, the compressed data canbe transferred as required while allowing execution of the compressionprocessing. This makes it possible to reduce the time required for datatransfer.

(2-5) Disaster Recovery Processing

Upon detection of failure in the primary site 100, the informationprocessing system 1 executes the disaster recovery (DR) processing toapply fail-over to the secondary site 200. Specifically, the DRmanagement program 460 starts the fail-over, and instructs switching ofthe site to the secondary site 200. If the DR method of multi-site typeis selected, the same system as that of the primary site 100 has beenconstantly operated in the secondary site 200 (DR environment has beenconstructed). Accordingly, the active environment can be easilyswitched. Meanwhile, if the method of pilot-light type is selected,normally, the secondary site 200 has only a minimum part kept stand-by.Accordingly, the resource is allocated to the part except the one keptstand-by, and the VM is started so that the DR environment isconstructed. The DR environment may be constructed by the DR environmentconstruction method of known pilot-light type. An example of theprocessing procedure will be described referring to FIG. 12 .

FIG. 12 is a flowchart representing the processing procedure example ofdisaster recovery processing implemented by the method of pilot-lighttype. FIG. 12 represents the processing procedure example of the DRmethod of pilot-light type for the disaster recovery (DR) processing tobe executed by the information processing system 1 upon detection offailure in the primary site 100. In this example, it is assumed that thecompressed data to be transferred from the primary site 100 to thesecondary site 200 have been stored in the second storage device 222 asthe object storage.

Referring to FIG. 12 , the DR management program 460 starts thefail-over to instruct the secondary site 200 to switch the site to thesecondary site (step S501).

In the secondary site 200, the cloud service management 230 confirmswhether or not the data transferred from the primary site 100 to thesecondary site 200 are compressed data (step S502). Specifically, instep S502, the determination may be made with reference to thecompression method 415 of the VM application management information 410.If the transferred data have been compressed (YES in step S502), theprocess proceeds to step S503. Meanwhile, if the transferred data havenot been compressed (NO in step S502), the DR processing is finished.

The processing to be executed in step S503 and subsequent steps will bedescribed. In the secondary site 200, the DR method of pilot-light typeis used for the VM 152. In order to allow the data to be accessible fromthe VM 252 as the DR destination, the data compressed for data transferhave to be decompressed for conversion.

For example, in most cases, the data to be used by the VM 1 whichexecutes the application 1 with low importance are stored in thelow-cost storage (in this example, the second storage device 222).However, the VM 252 cannot directly access the data for usage because ofthe second storage device 222 as the object storage. The storage device,for example, the block storage or the file storage like the firststorage device 221 allows data access from the VM 252. Accordingly, itis necessary to execute the processing of moving the data in the secondstorage device 222 as the object storage to the first storage device 221as the block storage to store those data.

The cloud service management 230 instructs execution of decompressionprocessing of the compressed data stored in the second storage device222 as the object storage, and the second storage device 222 executesthe decompression processing (step S503). Then volume to be provided tothe VM1 is generated in the first storage device 221 as the blockstorage, and the data decompressed in step S503 are stored in the volume(step S504).

The cloud service management 230 attaches the volume which stores thedata decompressed in step S504 to the VM1 (step S505), and finishes theDR processing. Execution of the processing in step S505 allows the VM1(VM 252) to access the data in the volume within the block storage.

The processing executed in steps S503 to S505 is not limited to the DRprocessing executed by the method of pilot-light type, but broadlyapplicable to the case where the storage system 220 in the secondarysite 200 is the object storage for storing the backup data (data derivedfrom copying and compressing the data to be used by the VM 152) of theprimary site 100 as a result of data transfer.

In the foregoing description, the processing procedure is executed uponthe fail-over. The processing executed in step S503 for decompressingthe compressed data stored in the second storage device 222 may bereplaced with the processing for decompressing the compressed data bystorage controller or hardware such as a circuit within the firststorage device 221, or other node and appliance of the cloud within thesecondary site 200. That is, the section where the processing ofdecompressing the compressed data is executed is not limited to the onewithin the second storage device 222, but may be the one within thefirst storage device 221 or any other section.

As described above, the information processing system 1 according to theembodiment is configured to determine various settings relating to datatransfer to the DR destination for each of the VMs 152 based on theimportance of the application 153 by implementing the DR method(pilot-light type and multi-site type) adapted to the service desired bythe customer using the application 153. This makes it possible toprovide the disaster recovery configuration adapted to the service(application) to be used by the customer. The information processingsystem 1 transfers data to the DR destination by compressing the datausing the compression method (compression algorithm) determined based onthe importance of the application 153 to store the compressed data inthe DR destination as they are until decompression is needed in the DRdestination. This may suppress the cost increase in the DR destination(secondary site 200) in the cloud environment, resulting in reduction inthe cost of overall disaster recovery system.

(3) Other Embodiments

The present invention is not limited to the above-described embodiment,but variously modified. In the following description, severalembodiments (modifications) according to the present invention will bedescribed. Explanations with respect to configurations and processingoperations of the information processing system 1, which are omitted inthe following modifications may be considered as being similar to thoseof the above-described embodiment.

(3-1) First Modification

The information processing system 1 may be configured to determine thetransfer data compression method (compression algorithm) by implementingthe processing procedure other than the transferred data compressionmethod determination processing as represented by FIG. 9 . Specifically,the determination is made based on the estimated required time (DRenvironment construction time) taken from the start of fail-over forconstructing the DR environment until the VM 252 as the DR destinationbecomes ready for start-up.

FIG. 13 is a flowchart representing another example of processingprocedure of the transfer data compression method determinationprocessing. Similar to the transfer data compression methoddetermination processing as represented in FIG. 9 , the transfer datacompression method determination processing as represented in FIG. 13 isexecuted by the DR management program 460 of the cloud management node300 for each of the VMs 152.

Referring to FIG. 13 , the DR management program 460 estimates thedecompression processing time per unit data size of the compression data(step S601). The DR management program 460 estimates the instancegeneration time per unit resource required for generating the instance(step S602). The instance generation time includes the time required forsecuring the resource and starting the VM 252.

Based on the number of resources required to be secured for constructingthe DR environment, and the instance generation time estimated in stepS602, the DR management program 460 estimates the required DRenvironment construction time taken from the start of the fail-over forconstructing the DR environment until the VM 252 as the DR destinationbecomes ready for start-up (step S603).

After each estimation is performed in steps S601 to S603, the DRmanagement program 460 selects the compression algorithm for compressionto attain data amount which allows the “compressed data decompressionprocessing time” to be within the DR environment construction time whichhas been estimated in step S603 from preliminarily provided multipletypes of compression algorithms. The selected compression algorithm isregistered in the compression method 415 corresponding to the VM of theVM application management information 410 as the data compression methodfor the VM 152 as the processing object (step S604). The “compresseddata decompression processing time” may be calculated based on the datacompression ratio derived from the compression algorithm, thedecompression processing time per unit data size which has beenestimated in step S601, and the number of resources required to besecured for DR environment construction used in step S603.

The thus determined compression method is implemented to compress thetransfer data to allow the information processing system 1 to decompressthe compressed data on the background of the processing associated withthe DR environment construction. In the foregoing case, it is estimatedthat the compressed data decompression processing may be finished beforecompletion of the DR environment construction. This allows the startedVM 252 to access the data without delay. Accordingly, the effect forreducing the time required for the fail-over can be expected.

In the foregoing modification, the compression algorithm is determinedfor each VM. However, it is possible for a still further modification ofthe transfer data compression method determination processing todetermine the compression algorithm for each data region in the singlevolume. Such determination is intended to secure the resource for the DRenvironment construction using the method of pilot-light type, andfinish the processing of decompressing the compressed data stored in theobject storage (second storage device 222) within the time for startingthe VM. As the compression algorithm is determined through fragmentationof the object, the data decompression processing may be securelyfinished before completion of the DR environment construction. Thismakes it possible to provide the effect of preventing delay in theoperation restoration time.

(3-2) Second Modification

As another modification of selecting the storage at the storagedestination of the transfer data, the information processing system 1may be configured to select the object storage or the block storage (orfile storage) as the storage at the storage destination of the transferdata based on the start-up time of the VM 252 upon the fail-over insteadof executing the processing procedure of the data transfer destinationdetermination processing as represented in FIG. 8 .

As described above, the VM 252 cannot access the compressed data storedas they are in the object storage (second storage device 222), andaccordingly, those data have to be moved to the block storage or thelike (first storage device 221). This may prolong the time required forexecuting a series of processing operations compared with the time forstoring the compressed transfer data in the block storage. If thestart-up time of the VM 252 is long, the problem hardly occurs. If thestart-up time of the VM 252 is short, the time taken for making the dataaccessible after start-up of the VM 252 may be delayed upon thefail-over.

The foregoing modification has been made from the above-describedviewpoint. The storage at the storage destination of the transfer datais determined based on the start-up time of the VM 252 upon thefail-over so that the VM 252 is allowed to access the decompressed dataimmediately after the end of start-up upon the fail-over (or after anelapse of the stand-by time subsequent to the end of start-up).

(3-2) Second Modification

Change in the form of operations of the customer who uses the storageservice derived from the information processing system 1 may vary theimportance of the application 153 to be used. In response to variationin the importance of the application, the information processing system1 may be configured to re-execute the respective processing operationsas represented in FIGS. 8 to 10 to update the respective correspondinginformation data to be determined based on the importance of theapplication (specifically, the transfer destination 414, the compressionmethod 415, the transfer method 416, the network 417 of the VMapplication information 410).

(3-3) Third Modification

In the embodiment as described above, the importance of the applicationis preliminarily determined based on the user's (customer's) instructionor analysis by the cloud management node 300. In the DR environmentwhere the user sets the DR method with level which differs for each VM,the DR management program 460 may be configured to determine theimportance of the application to be executed on the VM based on the DRmethod. Specifically, the importance of the application may bedetermined in accordance with each type of the DR method correspondingto the application. For example, in the case of using the pilot-lighttype, “low” importance is placed on the application, and in the case ofusing the multi-site type, “high” importance is placed on theapplication. Thereafter, the information processing system 1 (DRmanagement program 460) is allowed to determine the storage class of thedata transfer destination of the data transfer between the primary site100 and the secondary site 200, and compression method upon data storageutilizing the determined importance of the application in the similarmanner to the embodiment as described above.

The information processing system 1 may be configured to determine theDR method based on the predetermined importance of the applicationsimilar to the embodiment, the first and the second modifications, orbased on the predetermined DR method similar to the third modification.Based on the determined conditions, various settings for data transferto the DR destination (transfer destination storage, compression method,data transfer method, network type to be used for data transfer) aredetermined to allow the overall cost reduction accompanied withconstruction of the DR configuration while providing the DRconfiguration adapted to the service used by the user (customer).

The invention claimed is:
 1. A disaster recovery system provided with adisaster recovery configuration which allows a secondary site to recovera virtual computer and an application, which have been executed in aprimary site for supplying services in a normal time in response tooccurrence of failure in the primary site, comprising: the primary siteincluding a first server system for operating the virtual computer whichexecutes the application, and a first storage system for storing data tobe used by the first server system in a storage; the secondary siteincluding a second storage system for storing backup data for backing updata used by the first server system in a cloud storage, and a secondserver system for recovering the virtual computer and the application inconsideration of a correspondence relation in the primary site using thebackup data stored in the cloud storage upon occurrence of the failure;and a cloud management node for controlling an operation to constructthe disaster recovery configuration including the primary site and thesecondary site, and mediating data transfer for transferring the backupdata from the primary site to the secondary site, wherein the cloudmanagement node manages importance information indicating importanceplaced on a performance of each of the applications to be executed inthe primary site in correspondence with the virtual computer forexecuting the application, determines a disaster recovery method adaptedto the virtual computer and the application by selection from multipletypes of the disaster recovery methods based on the importanceinformation of the corresponding application for each of the virtualcomputers, and determines a content of a predetermined set item appliedto the data transfer of data to be used by the virtual computer based onthe importance information of the corresponding application for each ofthe virtual computers.
 2. The disaster recovery system according toclaim 1, wherein in the data transfer, the cloud management nodecompresses the backup data in the first storage system of the primarysite, and transfers the compressed data to the second storage system ofthe secondary site; and the second storage system stores the backup datawhich have been transferred from the primary site in a compressed state.3. The disaster recovery system according to claim 2, wherein: at leasta pilot-light type is included in the multiple types of disasterrecovery methods; and in the transfer of data to be used by the virtualcomputer to which the pilot-light type is applied, the second storagesystem stores at least a part of the backup data transferred from theprimary site in the compressed state until the recovery is started. 4.The disaster recovery system according to claim 2, wherein the cloudmanagement node determines a compression algorithm to be used forcompression of the backup data in the data transfer as a determinedcontent of the predetermined set item by selection from multiple typesof compression algorithms each at a different data compression ratio orspeed of decompressing the compressed data based on the importanceinformation of the corresponding application for each of the virtualcomputers.
 5. The disaster recovery system according to claim 2,wherein: the cloud management node estimates required environmentconstruction time taken from start of a fail-over for the recovery untilcompletion of start of the virtual computer for each of the virtualcomputers; and a compression algorithm which allows compression of thebackup data to an amount of data which attains time required fordecompressing the backup data to be within the estimated environmentconstruction time is selected from the multiple types of compressionalgorithms each at a different data compression ratio or datadecompression speed of the compressed data, and the selected compressionalgorithm is determined to be used for compressing the backup data inthe data transfer.
 6. The disaster recovery system according to claim 1,wherein: the second storage system has multiple types of cloud storageseach with a different resource usage cost or a different performance;and the cloud management node determines a storage destination of thebackup data in the data transfer as a determined content of thepredetermined set item by selection from the multiple types of cloudstorages based on the importance information of the correspondingapplication for each of the virtual computers.
 7. The disaster recoverysystem according to claim 1, wherein the cloud management nodedetermines a transfer method of the backup data in the data transfer asa determined content of the predetermined set item by selection frommultiple types of transfer methods including a synchronous copy and anasynchronous copy based on the importance information of thecorresponding application for each of the virtual computers.
 8. Thedisaster recovery system according to claim 1, wherein the cloudmanagement node determines a network type for transferring the backupdata in the data transfer as a determined content of the predeterminedset item by selection from multiple types of networks each at adifferent communication cost or communication speed based on theimportance information of the corresponding application for each of thevirtual computers.
 9. The disaster recovery system according to claim 1,wherein: the second storage system includes a first storage device whichallows the virtual computer generated by the second server system todirectly access data, and a second storage device which does not allowthe virtual computer generated by the second server system to directlyaccess data; and in the case where the backup data in the data transferare stored in the second storage device when the cloud management nodeinstructs the secondary site to execute a fail-over for the recovery,the backup data are decompressed to be stored in a volume generated inthe first storage device, and the volume is attached to the virtualcomputer for using the backup data.
 10. The disaster recovery systemaccording to claim 1, wherein in the case of designation of the disasterrecovery method applied to the virtual computer and the application foreach of the virtual computers, the cloud management node determines theimportance information of the application to be executed by the virtualcomputer based on the designated disaster recovery method.
 11. Adisaster recovery method implemented by a disaster recovery systemprovided with a disaster recovery configuration which allows a secondarysite to recover a virtual computer and an application, which have beenexecuted in a primary site for supplying services in a normal time inresponse to occurrence of failure in the primary site, the disasterrecovery system including: the primary site having a first server systemfor operating the virtual computer which executes the application, and afirst storage system for storing data to be used by the first serversystem in a storage; the secondary site having a second storage systemfor storing backup data for backing up data used by the first serversystem in a cloud storage, and a second server system for recovering thevirtual computer and the application in consideration of acorrespondence relation in the primary site using the backup data storedin the cloud storage upon occurrence of the failure; and a cloudmanagement node for controlling an operation to construct the disasterrecovery configuration including the primary site and the secondarysite, and mediating data transfer for transferring the backup data fromthe primary site to the secondary site, wherein the cloud managementnode: manages importance information indicating importance placed on aperformance of each of the applications to be executed in the primarysite in correspondence with the virtual computer for executing theapplication; determines a disaster recovery method adapted to thevirtual computer and the application by selection from multiple types ofthe disaster recovery methods based on the importance information of thecorresponding application for each of the virtual computers; anddetermines a content of a predetermined set item applied to the datatransfer of data to be used by the virtual computer based on theimportance information of the corresponding application for each of thevirtual computers.